Electric and plug-in electric vehicles require an interface to external charging devices. In order to promote standard interfaces among vehicle and charge station manufacturers, industry standards have been developed. One such standard is the SAE Electric Vehicle and Plug in Hybrid Electric Vehicle Conductive Charge Coupler (J1772) standard. The J1772 standard defines a charge coupler and the associated protocol required for transferring energy to the vehicle. The standard defines a common interface that all vehicle and charge station manufacturers are encouraged to follow.
A vehicle requires a means of waking up modules within the vehicle when a charge connector of electric vehicle supply equipment (EVSE) is connected to the charge port of the vehicle. One means of waking modules in the vehicle is with a control pilot signal defined by the J1772 standard. When a connection is established between the charge connector and the charge port, a control pilot signal is established between the EVSE and the vehicle. This signal can be used to wake up appropriate modules in the vehicle in order to initiate charging. The control pilot signal may maintain a signal level to keep the vehicle modules in a powered up state for extended periods of time while the charge connector is attached.